Z51 REFRIGERATION TEST 2025| ALL
QUESTIONS AND 100% CORRECT ANSWERS |
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The refrigerant unit that you have been assigned to is being taken out
of service for a major repair. You have been assigned to withdraw
refrigerant for storage in suitable containers. According to the NYC Fire
Code, you must ensure that the containers: - Correct-Answer-Are
approved by the US Dept. of Transportation
Which of the following best describes how the cylinder unloader
works? - Correct-Answer-Keep in the suction valve opened while the
compressor is in the return stroke
In most semi-hermetic compressors, the suction vapor is used to: -
Correct-Answer-Cool the motor
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The amount of refrigerant that flows through the orifices of an
economizer is determined by the: - Correct-Answer-Differences
between the high side and low side pressure
The installation of an inline refrigerant cleaning system is advisable: -
Correct-Answer-To remove impurities from the system
The type of refrigerant system that is least likely to leak refrigerant into
the building space that are being cooled: - Correct-Answer-Indirect
system
The suction pressure of a reciprocating compressor is 65 PSIG. The
discharge pressure of this compressor is 120 PSIG. The atmospheric is
14.7 PSI. The compression ratio for the given condition is closest to: -
Correct-Answer-1.69
A superheated vapor is: - Correct-Answer-Dry vapor above the
saturation temperature
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A refrigerant engineer verifies that a condenser water pump is
cavitating. Of the following, the most likely cause for this condition is: -
Correct-Answer-A faulty cooling tower water level controller
A centrifugal water pump is known as a lift pump when the: - Correct-
Answer-The water supply to the pump suction inlet is below the pump
level
A TXV is used to maintain constant: - Correct-Answer-Evaporator
superheat
The chilled water supply to the building is 55 deg F. If the chiller is being
used for human comfort, should you be concerned about this, and
why? - Correct-Answer-Yes, this temp is too high for human comfort
purposes
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The packing gland of a centrifugal pump serves to: - Correct-Answer-
The drip part of the packing gland gives evidence that there is water in
the pump
Capacity control of reciprocating hermetic compressor is typically
achieved through: - Correct-Answer-Operation of the hot gas bypass
valve
The most important reason to sub-cool the refrigerant in the condenser
is to ensure that: - Correct-Answer-A pure liquid refrigerant will enter
the metering device
A refrigeration engineer is logging readings from a reciprocating
system. Compressor discharge temperature have dropped significantly
and the suction line pressure is high. Which of the following that may
be causing this set of condition? - Correct-Answer-An expansion valve
that is open too wide